After sitting for several months while I was deployed, our 4Runner's transfer case actuator was sticking giving me a pair of flashing lights (the green 4wd light and the yellow center differential lock light). After I trawled the forums looking for ideas here's what I came up with:

- Engaging and disengaging the 4wd repeatedly is a good first step. In my case however, no amount of engage/disengage, rocking, coasting, forward reverse was getting any results.

- Crawling under the car with a buddy in the driver's seat changing the 4wd switch is a good way to see/ hear what the actuator is doing. On my 2008, it turns out there is an inspection port that you can unscrew and view a pointer dial that gives you an idea of what's going on inside the actuator.

- While under the car, grab the front and rear driveshafts and rotate them while the buddy cycles the switch. You can feel if the actuator is binding up / and whether the differential is engaging the front shaft. If it is binding, turning both the driveshafts slightly may help it engage.

- My motor was really frozen so I had to take another step. I removed the actuator bottom plate and was able to rock the motor coupling with a small screwdriver. I marked the gear's position and moved the motor shaft about 1 revolution forward, then back about 3-4 times. The motor felt less bound up after a couple of turns. (Take care opening the case bottom as there are gears that will come off their shafts and rest on the bottom plate. Just keep the bottom plate level as you lower it from the actuator and the gears will stay put. I had to loosen the three actuator attachment bolts and remove the one transfer case guard bolt that was in the way of lowering the bottom plate of the actuator.)

- I then put it back together and had my buddy cycle the 4wd switch again. I could see from the inspection dial that it was moving about 90 degrees at first, engaging the front shaft but still beeping. After a couple of cycles (and a twist of the rear shaft) it went all the way to 4wd hi. A couple more cycles and then to 4wd low. It seems to be shifting much more smoothly now and the lights glow steady when in 4 Hi/Lo, and when I lock the differential. The inspection dial shows it traveling about 240 degrees to the locked mark.

The actuator looked brand-new inside and had lube on the gears. I didn't lubricate the motors at this point since they seem to be much happier now.

BTW, the breather hose on the actuator case was problematic for several of the owners who posted problems. Toyota used a hose that has serrated flare on the end so it will slip over the breather fitting easily. I think these serrations crack over time resulting in a loose fit / falling off the fitting leaving the actuator exposed to water (some of the pictures of failed actuators revealed rust and crud over its components, clearly water had seeped in and made a real mess). I clipped off the end 1/4 inch of the hose to remove the flared end (which looked close to failure) and re-attached it for a nice snug fit.

Transfer Case Actuator


Inspection port / pointer dial


Inside Actuator to rotate motor coupling to free it up


Breather hose flared end removed


Thanks to all who have posted, I found it well documented how important it is to "use it or lose it" with these actuators so I'll be sure to use them weekly.

Bottom plate of Transfer case actuator removed from vehicle

Seeing a lot of stuck actuator posts lately. Hopefully this will help a few people get theirs unstuck without having to replace anything.

Seems like as the 4th gen 4Runners get older, the actuators are showing up either all gunked up or seized.

I have always been one for driving on the nearby dirt road or snow every month to keep the actuator lubed.

Honestly, I think the design is a poor one and I truly miss the old days of manually engaging with a shift lever the 4wd and lo aspects of the transfer case as in my previous 4wd pickups.

Toyota went for the 'more modern' and 'eye appealing' aspect of the dial rather than the so-called obtrusive shift lever.

The dial lever design is one of the achilles heels of the 4th generation 4Runner.

agreed.

I think too, that some of the failures were on fairly new rigs. its just a really bad design.

it would be MUCH better if it had a manual shifter.

How do you determine the correct timing for the gears when you replace the bottom plate back into the actuator?

That's the big question... So far everyone who has tried this has come close, but the system still shifts a bit funny after they've put it all back together again.

There's no literature stating what the timing should be to begin with (Toyota considers this a Non-Serviceable item, meaning you should never take it apart), and very few of us have one let alone two perfectly good known working actuators to take apart and compare.

So, What are my options?

4 Hi and center diff lock work fine but I can't engage 4 lo.

My 2006 LTD with the V8 was stuck when I bought it used in 2013. (I did not check it before purchase.) I just kept trying to engage it every so often and almost gave up on getting it to work. So, after a long drive on I/5 through Northern California when it was about 106 degrees, I tried it one more time. Finally, the actuator engaged 4lo. I was shocked but very happy. It now engages instantly and makes no noise at all. My advice, just keep trying, you might get lucky like me. I think in my case, the hot weather softened up the grease in the actuator gears and that helped it finally engage. Just my theory!

Hmm... and you're trying to engage it with the vehicle in Neutral? Have you tried having someone tap on the case with a rubber mallet while you engage 4Lo? If 4Hi is working it should engage 4Lo, they are on the same shift rod IIRC.

Unless he is full all wheel drive, then the rod only actuates the 4lo and the 2nd rod does center diff. I tried every trick in the book to free mine up. Never got it working so I ended up replacing it. Super easy job to do, everyone makes it out to be hard and takes forever. I had it done in 4-5 hours.

Yes. I put it in neutral and had a friend try 4-low repeatedly while I was under the truck tapping on the actuator. No joy. What bothers me is that while I hear something moving up front, I don't hear anything at all coming from the TC actuator. Even if the electric motor was seized wouldn't I hear it struggling to move?

• Where did you find the actuator by itself or did you replace the whole TC?
• So, I'm understanding that the 2003+ V6 has two motors and two shift rods, one for the center diff and one for 4-low?

My transfer case was perfectly fine, so I just replaced the actuator. Is your 4runner full time 4wd, or is is 2wd with the option to put it in 4hi/4lo? Mine is full time 4wd, then I can put it in 4Lo. Yes there is 2 motors wirh 2 rods, one for 4lo and one for center diff.

I highly recommend everyone take a look at this. It happened to me and I did the same thing except I also added a zip tie.

Looking at all the posts about this issue it does seem that temperature is a big factor. What about gently warming the actuator up with a heat gun (emphasis "gently")?

Second idea is to open up the cover plate just enough to insert the straw from my lithium spray.

If I have to go in there or replace the whole actuator I will but it seems like there is a great potential to make things worse. I'd rather start with the least invasive options.